


Rose and Violet Visit Underlust

by TaylorTheCreator14



Series: Rose and Violet's Visits [1]
Category: Undertale (Video Game)
Genre: Bone Caressing, Ectoplasm, Eye Licking, F/M, Heart Sex (Undertale), Oral Sex, Rough Sex, Underlust AU
Language: English
Status: Completed
Published: 2016-03-26
Updated: 2016-03-26
Packaged: 2018-05-26 05:51:32
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 2,997
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6226459
Author URL: https://archiveofourown.org/users/TaylorTheCreator14/pseuds/TaylorTheCreator14
Summary: <blockquote class="userstuff">
              <p>The Skelesisters found themselves in a Alternative Universe they didn't know where...They think they're back in Undertale...but the monsters they meet...will change everything.</p>
            </blockquote>





	1. Weird Appearances

**Author's Note:**

> Once I saw Underlust on Tumblr, I HAD to write a fanfic with it. The artist there is so amazing!~ 
> 
> Here! Check it out!: http://nsfwshamecave.tumblr.com/

Rose's POV

Me and my sister have woken up in an unknown universe...by some portal my sister made. Violet discovered a way to teleport to different timelines with her magic. Besides, she had better knowledge than me...and she's...mostly like Chara. But in the world we're in now? I haven't had the slightest idea...

"Welp...That went well..." Violet said, gritting her teeth and standing up, brushing herself off. 

"W-Well...What universe is this?" I asked, looking at her with the glowing purple eye of hers. My sister looked around as her eye stopped glowing, turning them back to her regular eyes.

She walked around, seeing the town differently, as well as the residents. "I don't know...but I can tell that everything here is different. The buildings, people, even...Grillby's?" Violet said, looking at the restaurant that's different than the one in Undertale...The sign was like...a nightclub's sign. Lighted Neon Pink. And from the inside were....raving lights blue, yellow, and pink? Without asking, she walked to the door, opening it. I followed right behind her. 

As we both walked in, our eyes were in surprise and shock. It was like a strip club! There was a pole in the back with some tables, as well as the place that was changed up a bit...but my eyes caught Grillby. He looked different too! There was slight blue color in his flames, his clothes were...a fishnet shirt?! And...white pants! Blush spread on my skull as I saw him...Violet has the same reaction as me, her skull flushed purple. 

"I think we've entered a strip club than a nightclub..." I said with a pink flushed skull. 

"You can say that again..." Violet shook her head, trying to get the blush off. 

We both sat down at a table, away from the pole that is. My mind is still trying to process from the place that we're in. Violet looked back at the pole, seeing a shadow of certain skeleton dancing on it...Her eye glowed purple brightly as she knew who it was. 

"Is that...Sans?!" She said with surprise and I look where she's looking, making my eye glow pink brightly. It...was Sans...but he looked different as well! He was wearing a black tank top with a light blue heart in the middle and it looked small...showing some of his spine, his jacket was like a vest that was dark purple with blue fur. On his hands were fingerless black gloves, something like a biker could wear. The pants were also black jeans and...he was wearing blue boots too! Is he...A stripper?! 

"Uhh...Violet...?" I called her as I saw her staring at Sans with her flaming eye. The purple flame did NOT go out in her eye as she kept looking at the skeleton. Violet looked like she had her eyes on something that she wanted for dear life...then suddenly, Grillby came to us, making me hold my breath. "Violet!" I whispered to her loudly and she got my attention...then she spotted Grillby in front of us. 

"Hello Ladies. What can I get for you today?" He asked with a smirk on his face. We immediately start trembling, trying to figure out what to say...then I opened my mouth. 

"J-Just ketchup please...!" I said with a nervous smile on my face, my bones shivering more than my voice. Violet nodded, having the same thing as me without speaking. The flame bartender nodded, walking to the counter. We've just witnessed...something weird and confusing. As we were in our confusing thoughts, Grillby came back with a tray, holding two small glasses of ketchup, placing them down in front of us. "T-Thank you..." I said with a smile, making the bartender smile back at me...then he went back to his station. 

Violet held her drink in her hand, trying to keep her SOUL sane as she was about to lose her mind. I drank mine quickly, trying to get it down my system...then I noticed someone coming towards us. A skeleton. The two of us kept our breaths held as we saw who it was...the one that was just on the pole! 

"Wow~ What do we have here?~ Two skeletons looking good." He said, leaning on his hand, looking at us with a smirk. It was Sans...the different Sans that is...My skull turned pink all the way as Violet held her breath. "The name's Sans. What's yours?~" The skeleton asked, dragging a finger slowly down my hoodie. 

* * *

 

"R-ROSE! My name is Rose! And this is my sister, Violet!" I yelled out my name, stuttering as he touched me. Violet nodded her head quickly. "And...I don't think you should be touching someone you've just met...!" The skeleton smirked at my reaction, licking his lips with a...purple tongue? Wait...THIS Sans has purple magic? That's very weird..."A-Anyways...Sans, w-why do you look like that?" I asked with a concerned face. He smirked at me. 

"This is what I always wear~" The skeleton said, lifting my chin. My eye glowed pink again as I shivered...then I felt something wet in my eye socket, making my head go dizzy. Sans...was licking my eye socket!! 

"S-S-SANS!!" I froze in place and shivered as the skeleton licked my eye socket. Violet's eye glowed purple with a flame as she watched with surprise...and she started to back away, leaving me in this mess. "V-V-V-Violet!! H-Help me over here!!" I begged with a pink skull and she just stood there...then she did something. Her hand glowed purple, spawning her Gaster Blaster. It charged it's beam...but then it vanished. Sans' eye glowed the same color as Violet's but in a heart shape. 

"What the hell...?" She said with shock as she was suddenly pulled in by magic. The skeleton stopped licking my socket, making me faint on the seat. Sans smirked at my sister, whispering something in her ear. Her eyes went wide as he heard that from his mouth...

_Let's Frick..._


	2. The Fricking is Beginning.

**Summary for the Chapter:**

> This is where the girls get the time of their lives!~
> 
> (*Fixes glasses* Please forgive me for my dirty sins...)

Violet's POV

This Sans told us to come to his house, which I probably think it's the same...and I think that Papyrus will be different as well...As we started walking out of Grillby's, Rose was still shivering as her eye still glowed pink.

"H-Heh...He licked you good didn't he...?" I asked with a nervous face and Rose looked at me with her glowing eye...then I shut up as I saw her mad look.

"Just shut up..." She said as she kept following Sans to his house. As we got there, it looked the same...except with the lights and such, like how the real Papyrus liked his home every time me and Rose visited him. Good times. Sans opened the door as we both gulped, walking inside.

The house looked the same except with different appearances...I wonder if Papyrus is home...

"Oh? Sans. You came back late." A voice said from upstairs on the second floor. Me and Rose looked up, seeing a skeleton...and he looked different...It was Papyrus. He was wearing a black jacket that barely covered his ribs...and it looks like the ectoplasm on his body was showing. Up to his spine to his legs. The jeans he wore were black as well with yellow straps around the thigh area, and the belt of course, has yellow hearts on it. His boots were yellow...not red. "Oh?~ What's this? Two skelegirls from a different dimension?" He asked with a smirk on his face as his heart-shaped eye glowed pink with a flame.

I gulped as my skull turned purple again. 

"U-Uh...! I-I'm Rose...and this is my sister...Violet..." Rose said, introducing ourselves. I waved nervously and then I felt a hand on my shoulder, sliding down my side. My pupils shrunk as I fell a tongue on my neck bones. 

"A-Ahh...! W-What are you doing...!?~" I asked with a nervous smile on my face as I kept shivering...then I suddenly was thrown behind a shoulder...Sans' shoulder. 

"Now...It's time for us two to play~" He said, walking upstairs with me. W-Wait a minute...is he going to FUCK ME?! 

"W-Wait! C-Come on now! Don't joke with me-R-Rose!!" I called out to Rose while I squirmed, where she was...wait a second...is Papyrus-"AHH!!" I screamed as I was taken into his room, the door closed behind us. 

* * *

 Rose's POV

I saw my sister being taken away by Sans and she called for help! While running to her, I was stopped in my tracks since someone held me from behind. "H-Hey! L-Let me go!" I said, squirming...and then...

"AHH!!" *SLAM!* I heard Violet's scream, then the door slam, and I was in shock as my eye glowed pink. Sans...took my sister away...and-

"Don't worry sweetface~ The Great Papyrus will take care of you~" Papyrus said, rubbing his hand on my cheek...I shivered as I watched with my glowing eye. "Now...let's see what's underneath this...~" He said, grabbing the zipper of my hoodie, pulling it down...then I stopped him, pushing him away. He gasped softly with surprise. 

"S-Stop it! W-What's the meaning of this...?!" I said with tears in my eye sockets, covering my ectobreasts with my hoodie. "M-My sister just wanted to explore this dimension and...and...then you suddenly want to...FUCK us?! I-I feel like this is molesting!" Spilling the thoughts out of my mouth, Papyrus sighed softly, walking towards me...which I held my guard up. "N-No! G-Get away!" Moving back, I shivered...then I felt hands gently holding my wrists...moving my arms away from my open hoodie....I froze in place.

"Who said anything about molesting....?~" Papyrus asked, whispering to me. "This is only pleasure...~" He opened my hoodie, rubbing one of my breasts, making me shiver as my skull blushed pink. 

"N-Nnn...~ N-No...stop..." I said softly with a red face...but his groping and rubbing didn't stop...I leaned on the wall, trying to endure it. "P-Pleasure...y-you say..." Looking away, I panted softly as I felt something wet on my nipples...Papyrus was licking them, like he would to a nice cream cone...

He looked to as he was enjoying himself...too much...then I my thoughts were cut off as I heard my jeans come undone. With a gasp, I looked down as they slid down my bones, showing my pelvic bone with a pink entrance...and...and...I didn't even knew that I summoned one...!

"Huh?~ What's this?~ You've already summoned an ectopussy?~ How lewd..." Papyrus said as he smirked, rubbing it gently. I gasped with embarrassment as he talked dirty to me. But I don't even know anymore...I moaned as he pleasured me slowly. 

"P-Papyrus...~ T-That feels so weird..." I said softly, moaning as I held onto the wall...

"Oh, it's going to get even more weird babe...~" He said, lifting my leg, putting it on his shoulder...then he started licking it, slowly. My eye glowed pink with a small flame as I felt pleasure coming up in my hips...Moaning with slight pleasure, I felt Papyrus kiss me deeply. His ecto tongue feels very...very hot...

"You like that?~ Do you want more baby girl...?~" He asked with a seductive tone, putting his fingers inside. I gasped, arching my back as he pumped them in and out, hard and fast. My mind was going crazy. I moaned like crazy, looking up with my glowing eye. "I can't tell if you don't say anything..." Papyrus said as he slowed down his fingers, making me squirm and whine softly. 

"N-No...P-Please...~ D-Don't stop...P-P-Papy...rus...~" I begged softly and he smirked, moving his fingers again but faster. My peak was about to be reached until he pulled them out, fully. "W-Why did you...Ah!" Gasping with surprise, my legs were both lifted up and I was leaning against the wall...then I felt something hard on the lips of my entrance. My eye shrunk as I watched Papyrus penetrated me...slowly...until it's the way inside...Gritting my teeth, I drooled. The skeleton was panting with lust...

"My god...You're tight as fuck...~" He said as he started to move. The thrusts were slow and careful, trying to help me get used to it...He kept moving, making me moan loudly as I wrapped my legs around his waist. His heart-shaped pupil glowed pink while it had a small flame. I could tell he was enjoying himself too much...

"P-Papyrus...!~" I moaned out his name as he sped up the thrusts, making me cover my mouth. He smirked, gripping my thighs tighter while moving his hips...but then suddenly, I heard moaning from upstairs...in Sans' room...

* * *

Violet's POV

I was tossed onto the bed as Sans closed and locked the door with his magic. My eyes widen as I watched him lick his teeth with a smirk. D-Damn...he's hot when he's rough with me...

"Looks like you're gonna have a good time~" The skeleton said, getting on top of my quickly. I gasped and held my breath as he unzipped my dark purple hoodie, revealing my ectoboobs...D-Didn't know I summoned them! "Oh my...~ So nice and soft...You were really waiting huh?~" He asked, caressing them. I shivered at the touch of his boney fingers on my ectoskin...

"N-No I didn't..." I said with a shivering voice, making the skeleton smirk more as he slid his hand down to my jeans, rubbing the crotch of them. I arched my back from the touch, making me go insane by the pleasure I was getting. Hearing the zipper go down, Sans moved his hand down some more, fondling the bone. "Nngh!~" Gritting my teeth, I moaned quietly. "O-Oh my god Sans..."

The skeleton smirked at my reaction, taking off my jeans and tosses them aside. I closed my legs as the ectoplasm covered them, making Sans click his tongue. 

"Now now...~ No need to hide it hot stuff...~" He said, putting his hands on my legs and spreading them. I gasped as I shivered with embarrassment...then I felt something slick and wet on my bone...

"A-AHH!!~ S-Sans!~ D-Don't lick it...!!~" I begged loudly as I looked down, seeing the skeleton pleasure me with his tongue. He was enjoying himself t-t-too much...! As he slid his tongue between the lips of my entrance, he thrusted it inside, making me scream.

"But...you taste sooo fucking good Violet...~" He said, spreading those lips with his fingers, licking the clit. That's when I lost it...My hand glowed purple, making the skeleton gasp as his pupils shrunk. I put him on his back and straddle him, looking down at him with lust. 

"Hah...hah...Y-You're too damn fast..." I spoke, undoing his jeans and pulling them down. His ectocock was really erect, making me amused. It's about time I return the favor. Sans watched as he blushed, smirking at the sight of me turning the tables. I held it in my hand, stroking it...My god...it's so hard and hot...I started licking the tip, swirling my tongue around it. The taste was...weird but in a good way. 

"Ahh...Fuck...~" I heard Sans said, rubbing my head. Humming with amusement, I sucked on it slowly, moving my head down as well...My lust was uncontrollable at the moment, making myself feel all hot...This is so good that I...couldn't stop.

Bobbing my head, I suck the skeleton off. He was moaning with ecstasy, making me proud. Well, that's what I thought...until Sans held my skull, thrusting into my mouth. My pupils shrunk as I gagged, choking a little...but I didn't care. "God fuck!!~ I'm going to cum in that pretty mouth of yours...~" He said, smirking at me as I kept gagging. He's really...a hot one and hard too...Which makes it hard to understand him. Do...the brothers do this with every monster? Or do they-

"G-GHH!!!~" My thoughts were cut off as I felt a warm and sticky liquid in my mouth, making my pupils shrink. He...came inside my mouth. The cum of course...was sweet to me as I swallowed it all. Moving my head away, I looked at Sans with lust. "W-Was...that good enough for you...?~" I asked, seeing him smirk at me. 

"Well, that wasn't enough to satisfy me...~" The skeleton said, putting me on my back and lifting my legs up. I gasped as I looked at his cock, positioned at my entrance...Now I know what he's doing...! 

"S-Sans wait...! I don't know about-" I was cut off as he thrusted inside of me, making me grit my teeth and drool. The truth is...I haven't been penetrated in a long time...and I've become so tight...! Shivering from the impact, the skeleton started moving his hips, forcing me to moan out with lust. It's so good...! "S-Sans...!~" I said, looking at his heart-shaped pupil that was glowing purple with a small flame.

"Shit...You're...fucking tight...!~ And I love it!~" Sans said with a smirk, panting with his ectotongue out as he kept moving. I feel like melting right now as I was starting to sweat...then I heard loud moaning coming from downstairs...assuming that was Rose...

* * *

Time Skip!~

* * *

Rose's POV

I woke up asleep on the snow...That was...incredible pleasure and...H-Huh? I looked around, seeing Violet asleep as well. I smiled and hugged her as we glowed pink and purple...Well, that was a weird but...amazing universe. But it's time for us to go...maybe...we'll visit them again...Although I did notice ONE thing...there was phone numbers in each of our hoodie pockets...We teleported back to Undertale with smiles on our faces...

 

**Notes for the Chapter:**

> Niel...please spare me for these dirty sins...

**Author's Note:**

> I'm so sorry...I have SUCH dirty sins right now...


End file.
